Refrigeration evaporator



Dec. 22, 1953 F. A. SCHUMACHER REFRIGERATION EVAPORATOR Filed Oct. 2,- 1951 v Inventor- Fr-anK A. Sch um-acher H is Attorn ey Patented Dec. 22, 1953 UNITED STATES PATENT OFFICE REFRIGERATION EVAPORATOR Frank A. Schumacher, Erie, Pa., assignor to General Electric Company,

York

a corporation of New Application October 2, 1951, Serial No. 249,367

My invention relates to evaporators and more particularly to evaporators for use in household refrigerators.

' v l oodstorage compartments of household refrigerators are frequently, cooled by evaporators disposed within the food storage compartment and exposed to the airtherein. In the conventional usage, the evaporator is disposed near the top of the food storage compartment so that natural circulation of air is secured. In order to a'voidthe necessity for manual defrosting or for providing automatic devices to effect defrosting,

'it may be desirable to operate the evaporator on a. defrosting cycle; that is, to operate the evaporatorwithin a range of temperature such that during the idle period of the refrigerating unit, the evaporator rises to'a sufliciently high tem- 4 Claims. 11. 62103) perature to effect melting of all frost collected thereon during the operating period of the refrigerating unit. With the evaporator mounted at" the top of the food storage compartment, it will be apparent that the water resulting from the melting of frost on the evaporator may fall downwardly'onto the food stored in the compartment. Such dripping of moisture on to the food is, of course, undesirable. In the copending application of James F. Young, Serial No. 249,361, filed October 2, 1951, and assigned to the assignee of the present invention, an evaporator configuration and mounting for facilitating drainage of water from the evaporator to the rear of the compartment and for minimizing drippage of water onto the food stored below the evaporator is described and claimed. The evaporator which forms the invention of James F. Young satisfactorily provides for the drainage of water from the serpentine extruded tubing which forms the evaporator surface. However, to provide rigidity to an evaporator of this type, to provide for mounting, and to further improve the appearance, it may be desirable to include at the forward and rear ends of the parallel passes of the evaporator mounting or trim strips. While the passes of evaporator tubing extend in a downwardlyinclined direction from the front to the rear of the compartment, the'mounting or trim strips occupy a generally vertical plane extending transversely of the compartment. Accordingly, water resulting from the melting of frost collected on these strips could be a source of drippage downwardly onto the food stored in the compartment. By my invention a particular configuration of at least the forward strip is provided which facilitates drainage of the water from the strip onto the tion will become apparent as the following description proceeds, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming part of this specification.

In carrying out the objects of my invention, an evaporator such as that described and claimed in the aforementioned Young applicationis employed. This evaporator includes an extruded section arranged in serpentine configuration to provide a plurality of parallel passes connected at their ends by loop portions. The extruded section includes a lower tubular refrigerantconducting portion and a fin extending upwardly therefrom. The evaporator is mounted at. the top of the food storage compartment with the parallel passes extending parallel to the sides of the compartment, and the evaporator is inclined downwardly toward the rear so that water collecting on the aforementioned extruded section drains toward the rear of the evaporator. A trim or mounting strip is connected, in accordance with my invention, to at least the forward loop portions and extends transversely of the storage compartment. The lower edge of this strip is formed in saw-tooth configuration, with the lower tips of the teeth arranged to discharge water therefrom onto the loop portions of th aforementioned extruded section.

For a better understanding of my invention, reference may be had to the accompanying drawing in which Fig. 1 is an elevation view, partly broken away, of a portion of a refrigerator incorporating an embodiment of my invention. v

Fig. 2 is an enlarged plan view of a portion of the'evaporator of Fig. 1. a

Fig. 3 is an enlarged elevation view, partly in section, of the evaporator shown in Fig. '1;

Referring now to the drawing, there is shown a refrigerator I including an outer metal wall 2-.

The refrigerator includes an inner wall or liner 3 spaced from the outer wall 2 and defining a food storage compartment 4. The space between the inner and outer walls is filled with a suitable thermal insulating material 5. The access opening 5 at the forward portion of the food storage compartment 4 is closed by a door I. A particular refrigerator shown is a combination refrigerator which includes a freezer or frozen food compartment (not shown) closed by the door 8. The lower compartment 4 is provided for the storage of fresh foods and the like.

The liner 3 includes a top wall 9 which is formed to slope downwardly from 'th'efront to the rear of the food storage'compartmentA and includes a depending portion or'kfiange In at the forward end thereof. The liner further includes a rear wall i I. An evaporator l2is provided for cooling the food storage compartment 4. The forward portion or end of the evaporator H ,is supported from the depending portion H! of the top wall 9 by brackets, one of which is-shown at [3. The rear portion or end of the evaporator I2 is supported by studs, one of which is shown at M, which are mounted on the rear wall ll of the linert.

As described and claimed in the aforementioned Young application, the evaporator i2 is formed from a continuous extruded section which is-shaped into a serpentine configuration includinga plurality of parallel straight portions i5 and a plurality of connecting loop portions. The loop portions connecting the ends of the adja cent straight portions at the forward end of the evaporator are indicatedat it, and the loop portions connecting the ends of adjacent straight portions at the rear end of the evaporator are indicated at H. The continuous extruded section l5 includes a lower tubular portion [8 for conducting refrigerant through the evaporator and an upwardly extending fin l9. As shown in Fig. 1, the evaporator i2, whose serpentine configurations are arranged in oneplane, is inclined downwardly toward the rear of the compartment 4 atanangle of about 18.

In order to avoid'the necessity of manual defrosting of the evaporator H1, or of providing automatic defrosting mechanisms, the evaporator i2 'is operated within a range of temperatures extending above and below the freezing point. of water. The .higher temperature is chosen such that, in combination with the durationof the idle period of the refrigerating unit, all frost which has collected on'the evaporator during the operatingperiod of the refrigeratingunit is melted during the idle period. Water collects on the evaporator from the melting frost, during the idle period of the refrigerating unit, Because of the configuration of the evaporator, this Water drains toward the rear of the compartment 4 and into a trough 2E3 primarily along the lines of intersection 2l between the fin i9 and the tubular portion 18. Additional grooves 22 may be provided in the finds above the line of intersection 21 to further assist in draining thewater to the rear. It can be seen that,by the above construction, water collecting on the extruded section of the evaporator is directed to the rear of the evaporator and discharged into the trough 20. The structure described thus far is not. my-invention but is described and claimed in the aforementioned Young application.

However, in order to provide'rigidity to, the

evaporatoryto provide for the mounting thereof,

and to improve the appearance, it is desirable to providea mounting or trimstrip :at, least along other suitable fastening devices.

4 the forward end of the evaporator, and preferably along both the forward and rear ends of the evaporator. In accordance with my invention such mounting or trim strips are provided with a configuration which minimizes drippage of water from these strips onto the food stored in the compartment 4. Thus an elongated trim or mounting-strip 23 is provided at the forward end of the evaporator J2 and a corresponding mounting or trim strip 24 is provided at the rear end of the evaporator. The strip 23 is secured to the forward loop portions It by rivets 25 or Similarly, the strip H-issecured to the rear loop portions I! by rivets or other suitable fastening devices.

The ends of the-strip 23, one of which is shown suitable fastening device.

Since the strips 23 and 24 extend transversely of the compartment 4 in a generally horizontal direction rather than being inclined downwardly to the rear as are'the straight portions} [5 of the evaporator, water collecting on these strips has a normal tendency to drip directly downwardly therefrornonto the food stored in the compartment 4. To overcome this tendency, the. lower edges of each of these strips are formed of sawtooth. configuration. Thus,the lower edge of the strip 23 includes a plurality of dependingteeth 29, The lower, ends or tips 30 of each'of the teeth 29 are disposed immediat'ely'adjacent a corresponding one of the forward loop portions It. The edges 35 of each of the depending teeth 29 are inclined downwardly toward thetip 30 so as to direct water collecting on the stri 23 to ward the'tip 333. The greater theangle of edges 3| relative to the horizontal the greater the tendency for all water collecting on the strip 23 to flow to the tips 30; however, I have found an angle at 24 with the horizontal to be, satisfactory. The tip 30 of each of the depending teeth '29 is positioned substantially at the midpoint of the corresponding loop portion 16 and tion i8 and is'the'n directed in accordance with the inventiondescribed and claimed in the aforementioned You ng application along this line of intersection 21 to the rear end of the evaporator and then ultimatelydischarg'ed into the trough 20. While the tips '30 of the depending teeth 29 have been shown disposed at the line of intersection 2|, it will be apparent that the tips 30 could be, if desired, disposed above this line of-intersection 2!, the water discharging from the tips 35 flowing downwardly into the line of intersection 2! or into the grooves 22 for disposition in the manner described above.

While the rear strip 2d may be constructed similarly to theforward strip 23 including. depending teeth with tips adjacent the rear loop portions l-Lit is not necessary to employ this configuration for the rear strip 26 Where a trough, as the trough 2! in-the form shown, extends the full width of the evaporator below the rear strip 24. Accordingly, inthe form illustrated, the rear strip'24 has 'a straight horizontal lower edge.

The strips 23' and 2G impart rigidity to the evaporator formed from the serpentine configuration of the extruded section and these strips further are employed for mounting the evaporator within the storage compartment 3. Thus, the strip 23 is secured to the bracket I3 by screws or other suitable fastening devices, one of which is shown at 32. Openings, one of which is shown at 33, are provided in the rear strip 24 for receiving the studs I4 to mount the rear end of the evaporator 12 on the rear wall I l.

While I have shown and described a specific embodiment of my invention, I do not desire my invention to be limited to the particular construction shown and described and I intend, by the appended claims, to cover all modifications within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent in the United States is:

1. A refrigerator including a liner defining a food storage compartment, an evaporator mounted at the top of said compartment for cooling said compartment, said evaporator comprising an extruded section formed into serpentine configuration including a plurality of parallel straight portions arranged in a plane and a plurality of forward and rear loop portions connecting the ends of said straight portions, said extruded section including a tubular refrigerant conducting portion and a fin portion extending upwardly therefrom, said evaporator being disposed with said straight portions extending parallel to the sides of said compartment and being inclined downwardly toward the rear of said compartment for facilitating drainage of water from said evaporator, and a strip extending along the forward edge of said evaporator and secured to said forward loop portions, said strip being of saw-tooth configuration on its lower edge, each of the depending teeth being disposed adjacent a corresponding loop portion with the tip of each of said depending teeth being disposed substantially at the line of intersection of said tubular portion and said fin portion.

2. A refrigerator including a liner defining a food storage compartment, an evaporator mounted at the top of said compartment for cooling said compartment, said evaporator comprising an extruded section formed into serpentine configuration including a plurality of parallel straight portions arranged in a plane and a plurality of loop portions connecting the ends of said straight portions, said extruded section including a tubular refrigerant-conducting portion and a fin portion extending upwardly therefrom,

said evaporator being disposed with said straight portions extending parallel to the sides of said compartment and being inclined downwardly toward the rear'of said compartment for facilitating drainage of water from said evaporator, and a strip extending along the forward edge of said evaporator and secured to said forward loop portions, said strip being of saw-tooth configuration on its lower edge, each of the depending teeth having its lower tip disposed substantially at the mid-point of its corresponding loop portion, said tip being substantially at the line of intersection of said tubular portion and said fin portion, the

upper ends of each of said depending teeth being disposed substantially midway between adjacent straight portions of said extruded section.

3. A refrigerator including a liner defining a food storage compartment, an evaporator mounted at the top of said compartment for cooling said compartment, said evaporator comprising an extruded section formed into serpentine configuration including a plurality of parallel straight portions arranged in a plane and a plurality of forward and rear loop portions connecting the ends of said straight portions, said ex truded section including a tubular refrigerantconducting portion and a fin portion extending upwardly therefrom, said evaporator being disposed with said straight portions extending parallel to the sides of said compartment and being inclined downwardly toward the rear of said compartment for facilitating drainage of water from said evaporator, and a strip extending along the forward edge of said evaporator and secured to said forward loop portions, said strip being of saw-tooth configuration on its lower edge, each of the depending teeth being disposed adjacent a corresponding loopportion with the tip of each of said depending teeth being disposed substantially at the line of intersection of said tubular portion and said fin portion, the lower edges of said teeth forming an angle of approximately 2 l with the horizontal.

4. A refrigerator including a liner defining a food storage compartment, an evaporator mounted at the top of said compartment for cooling said compartment, said evaporator comprising an extruded section formed into serpentine configuration including a plurality of parallel straight portions arranged in a plane and a plurality of forward and rear portions connecting the ends of said straight portions, said extruded section including a tubular refrigerant-conducting portion and a fin portion extending upwardly therefrom, said evaporator being disposed with said straight portions extending parallel to the sides of said compartment and being inclined downwardly toward the rear of said compartment for facilitating drainage of water from said evaporator, a strip extending along the forward edge of said evaporator and secured to said for-- ward loop portions, and a second strip extending along the rear edge of said evaporator secured to said rear loop portions, at least the forward of said strips being of saw-tooth configuration along its lower edge, each of the depending teeth of each of said strips being disposed adjacent a corresponding loop portion with the tip ofeach said depending teeth being disposed substantially at the line of intersection of. said tubular portion and said fin portion.

FRANK A. SCHUMACHER.

References Cited in the file of this patent UNITED STATES PATENTS 

